Router

ABSTRACT

A portable electric router having a large diameter helical compression spring encircling a router bit drive motor and biasing the motor to a retracted position, and an adjustable stop and one-way locking device for presetting and locking the motor in an extended operating position and providing for plunge cutting to a depth of cut established by the operation position of the motor.

United States Patent Ambler et al.

[11] 3,791,260 Feb. .12, 1974 ROUTER Inventors: E. Curtis Ambler;Kestutis Damijonaitis, both of Newington; Paul A. Ketchpel, Simsbury,all of Conn.

The Stanley Works, New Britain, Conn.

Feb. 17, 1972 [73] Assignee:

Filed:

App]. No.:

US. Cl. 90/12 D, 144/134 D Int. Cl. 1323c l/20 Field of Search.....90/12 D; 144/134 D, 136 C,

[56] W Iiiiiig Cited FOREIGN PATENTS OR APPLICATIONS 843,011 7/1952Germany 144/134 D Primary Examiner-Francis S. Husar Attorney, Agent, orFirm-Prutzman, Hayes, Kalb & Chilton 5 Claims, 3 Drawing Figures ROUTERThe present invention relates generally to routers and more particularlyto a router having new and improved means for establishing the depth ofcut of the router.

It is a primary aim of the present invention to provide a new andimproved portable electric router manually operable for keeping therouter bit in a retracted position above a lower support base of therouter between cutting operations and providing for plunge cutting to apre-established depth.

It is another aim of the present invention to provide a new and improvedrouter depth of cut setting mechanism facilitating retention of therouter bit in a retracted safe position during nonuse.

It is a further aim of the present invention to provide a new andimproved router of the type desribed having an economical and compactassembly of parts.

Other objects will be in part obvious and in part pointed out more indetail hereinafter.

A better understanding of the invention will be obtained from thefollowing detailed description and the accompanying drawings of anillustrative application of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a side section view, partly broken away and partly in section,taken substantially along line l l of FIG. 3 of a preferred embodimentof a router incorporating the present invention;

FIG. 2 is a partial side view, partly broken away and partly in section,of the router showing an adjustable stop and one-way locking device ofthe router; and

FIG. 3 is a reduced top view, partly broken away and partly in section,of the router.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings indetail, wherein like numerals represent like parts throughout theseveral figures, a preferred embodiment of a router incorporating thepresent invention comprises a base subassembly l2 and a motorsubassembly 14 having in a'conventional manner an electric motor 15which a driven collet ,16 for supporting a suitable router bit 17. Thebase subassembly l2 and motor subassembly 14 may for example begenerally like that shown in U. S. Pat. No. 3,587,387 of Milford D.Burrows, et al. and entitled ROUTER, excepting that the motorsubassembly 14 and base subassembly 12 are differently designed forsupporting the motor subassembly 14 on and adjust ing it relatively tothe base subassembly 12 in accordance with the present invention.

More particularly, the base subassembly 12 comprises by a base casting19 with an upstanding support collar 18 and a plastic base plate 21 witha flat support face 20. The motor subassembly 14 comprises a motorsupport sleeve 23 with an outer teflon coated cylindrical surface forsupporting the motor 15 within a conforming cylindrical bore of thesupport collar-18 for relative movement of the subassemblies 12, 14parallel to the motor shaft axis and perpendicular to the flat supportface 20. A cast ring 24 (described hereinafter in more detail) ismounted on the upper end of the 2' motor support sleeve 23, and a largeset screw 25 is mounted in a lug 26 of the ring 24 and extends throughan opening in the sleeve 23 to bear against the motor 15 such that themotor 15 can be inserted into the sleeve 23 to engage a lower inner lip27 thereof and be locked in place by the set screw 25. Four angularlyspaced threaded fasteners 28 are screwed into the lower end of thesleeve 23 such that the fastener heads are engageable with a lower edge29 of the support collar 18 to provide a stop for establishing the upperlimit position, shown in FIG. 1, of the motor subassembly 14 relative tothe base subassembly l2. Suitable slots 30 and transverse openings 31are provided in the base casting 19 for receiving the fastener heads andfor removing the fasteners 28 for permitting removal of the motorsubassembly 14.

An upstanding cylindrical shield 32 is secured by suitable threadedfasteners 33 onto the base casting 19 with the lower edge of the shield32 engaging a shoulder 34 formed on the base casting 19 and such thatthe shield extends upwardly coaxially with the support collar 18 toenclose the lower end of the collar. The cast ring 24 has a collar 42secured onto the motor support sleeve 23 by threaded fasteners 43extending outwardly through the sleeve into the lug 26 and threeadditionally angularly spaced lugs 44 of the collar 42. The ring 24 hasan enlarged depending cylindrical skirt or shield 45 having a largerdiameter than the upstanding shield 32 and which, as shown in FIG. 1,slightly overlaps the upstanding shield 32 with the motor subassembly 14in its fully retracted position. The coaxial cylindrical shields 32, 45are dimensioned for telescoping association to permit the motorsubassembly 14 to be shifted axially downwardly from its upper or fullyretracted position. The lower limit position of the motor subassembly 14on the base subassembly 12 is established by the engagement of the upperedge 47 of the motor support collar 18 with the inner edge 48 of thering 24. The base support collar 18 accordingly has suitable notches 49for receiving the mounting lugs 26, 44.

A downwardly opening annular groove 50 is provided in the ring 24inwardly of the depending skirt 45 and an opposed upwardly facingannular shoulder 56 is provided on the base casting 19 inwardly of theupstanding shield 32. A large diameter generally helical compressionspring 60 encircling the motor support collar 18 is mounted between theannular shoulder 56 and annular groove 50 to bias the motor subassembly14 to its fully retracted position. The compression spring 60 as well asthe motor support collar 18 and an intermediate portion of the motorsupport sleeve 23 are encased by the shields 32, 45 to provide forprotecting the bearing surfaces of the sleeve 23 and collar 18 againstforeign matter and for preventing contact by the motor operator with thecompression spring 60.

A combined guide and locking rod is supported upright on a lug 72 of thebase casting 19. The rod has a lower reduced end 74 with a cylindricalportion 76 for accurately locating the rod 70 to extend parallel to themotor or router bit axis ana a threaded portion 78 for securing the rodto the base casting 19 with a nut 80. The ring 24 has a pair of axiallyspaced lugs 84, with oil impregnated bushings 86, 87 respectivelyreceiving upper and intermediate portions 88, 89 respectively of the rod70. The motor subassembly 14 is thereby angularly keyed to the basesubassembly l2 and guided for axial movement relative to the basesubassembly.

A generally U-shaped collar 92 is mounted on the upper portion 88 of therod 70 between the lugs 84, 85 and a threaded winged fastener 94 isreceived in an opening 95 in one leg of the collar and threaded into theother leg of the collar for manually locking and unlocking the collar tothe rod 70. Accordingly, the collar can be adjustably positioned on theupper portion 88 of the rod 70 between the lugs 84, 85 and therebyprovides an adjustable stop for setting a lower operating postion of themotor subassembly 14 with the lower face of the upper lug 84 inengagement with the upper face of the stop collar 92. A scale 96 ismounted on the skirt 45 for directly reading the permitted amount ofaxial displacement of the motor subassembly established by the stopcollar 92.

The router bit is preferably mounted in the collet 16 so that, with themotor subassembly 14 fully retracted, the end of the router bit is abovethe lower face 20 of the base subassembly 12. In that event, the readingon the scale 96 (at the upper face of the collar 92) equals the total ofsuch distance plus the available depth of cut. The stop collar 92 isaccordingly set to establish the desired depth of cut.

The upper lug 84 is formed with a cylindrical cavity 102, and areleasable one-way lock assembly 104 is mounted within the cavity 102for locking the motor subassembly 14 in its extended or operatingposition in engagement with the stop collar 92. The lock assembly 104comprises an axially tapered ring or wedge 106 press fit within thecavity 102 and a pluraltiy of angularly spaced locking balls 108 mountedwithin a suitable ball cage 109 for engagement with a wedging surface lof the ring and the outer cylindrical surface of the rod portion 88. Theball cage 109 is biased downwardly by a helical compression spring 116mounted between the ball cage 109 and a cap 118 threaded into the outerend of the cavity 102. The balls 108 are thereby biased into engagementwith the wedging surface 110 and rod 70 and the axial taper of thesurface 110 is selected to provide a one-way lock for locking the motorsubassembly 14 to the rod 70 against the bias of the main return spring60. In the shown embodiment a taper of 26 is used and the balls 108 arepreferably roughened as by sand blasting and the rod portion 88 has aground finish with a black'oxide finish to provide improved locking.

A lock release lever 122 having an inner ring portion 124 mounted on theball cage 109 is provided for pivoting the ball cage 109 upwardlyagainst the bias of the compression spring 116 (e.g., by liftingmanually the lever 122) and for thereby withdrawing the locking balls todisengage the lock and permit the motor subassembly 14 to be retractedby the spring 60 to its fully retracted position. The lever 122 extendsthrough an opening 126 in the lug 84 and a washer or seal 128 is mountedon the lever 122 to provide a cover for the opening 126 to excludeforeign matter from the lock cavity 102.

Thus it can be seen that the depth of cut of the router can be readilyestablished by selectively positioning the stop collar 92 and by thendepressing the motor subassembly 14 against the bias of the spring 60until it engages the stop collar 92. The router can be employed forplunging the router bit into a workpiece by presetting the stop collar92 as desired, placing the router on the workpiece, turning the routermotor on and depressing the motor subassembly 14 until it engages thestop collar 92.

As will be apparent to persons skilled in the art, variousmodifications, adaptations and variations of the foregoing specificdisclosure can be made without departing from the teachings of thepresent invention.

We claim:

1. In a portable router having a base subassembly with a motor supportand a bottom router supporting face and a router bit drive motorsubassembly mounted on the motor support with its axis extendingperpendicular to the router supporting face and for axial adjustmentrelative to the base subassembly for adjusting the depth of cut of therouter, the improvement wherein the router comprises spring meansaxially biasing the motor subassembly in one axial direction relative tothe base subassembly for retracting the drive motor subassembly, whereinone of said subassemblies comprises a rod extending parallel to the axisof relative movement of the subassemblies, wherein the other of saidsubassemblies comprises releasable one-way locking means engageable withthe rod for locking the motor subassembly against movement in said oneaxial direction by the spring means, wherein the router comprisesadjustable stop means for limiting the relative movement of the motorsubassembly in the opposite axial direction and axially adjustable forpresetting the depth of cut of the router, wherein the motor support isa collar and the router bit drive motor subassembly comprises a motormounted within the collar for said axial adjustment, wherein the baseand motor subassemblies have axially spaced opposed annular surfacesencircling the motor, and wherein the spring means comprises a helicalcompression spring interposed between said opposed annular surfaces forbiasing the motor subassembly in said one axial direction.

2. In a portable router having a base subassembly with a motor supportand a bottom router supporting face and a router bit drive motorsubassembly mounted on the motor support with its axis extendingperpendicular to the router supporting face and for axial adjustmentrelative to the base subassembly for adjusting the depth of cut of therouter, the improvement wherein the router comprises spring meansaxially biasing the motor subassembly in one axial direction relative tothe base subassembly for retracting the drive motor subassembly, whereinone of said subassemblies comprises a rod extending parallel to the axisof relative movement of the subassemblies, wherein the other of saidsubassemblies comprises releasable one-way locking means engageable withthe rod for locking the motor subassembly against movement in said oneaxial direction by the spring means, wherein the router comprisesadjustable stop means for limiting the relative movement of the motorsubassembly in the opposite axial direction and axially adjustable forpresetting the depth of cut of the router, and wherein the releasableone-way locking means comprises a plurality of locking balls around therod, and an annular axially tapered ring surrounding the balls andoperable to wedge the balls into engagement with the rod to lock themotor subassembly against movement in said one axial direction.

3. A router according to claim 1 wherein the motor subassembly comprisesa ring encircling the motor and having a first of said opposed annularsurfaces and an annular depending skirt encircling said compressionspring, and wherein the base subassembly comprises an annular upstandingshield encircling the compression spring and having a telescopingrelationship with said skirt permitting said axial adjustment of themotor sub-, assembly.

' 4. A router according to claim 2 wherein the releasable one-waylocking means comprises a ball cage, cage spring means for biasing theball cage in one direction for positioning the balls for being wedged bythe 1 ring into locking engagement with the rod, and means for manuallyretracting the ball cage against the bias of means on the dependingskirt.

1. In a portable router having a base subassembly with a motor supportand a bottom router supporting face and a router bit drive motorsubassembly mounted on the motor support with its axis extendingperpendicular to the router supporting face and for axial adjustmentrelative to the base subassembly for adjusting the depth of cut of therouter, the improvement wherein the router comprises spring meansaxially biasing the motor subassembly in one axial direction relative tothe base subassembly for retracting the drive motor subassembly, whereinone of said subassemblies comprises a rod extending parallel to the axisof relative movement of the subassemblies, wherein the other of saidsubassemblies comprises releasable one-way locking means eNgageable withthe rod for locking the motor subassembly against movement in said oneaxial direction by the spring means, wherein the router comprisesadjustable stop means for limiting the relative movement of the motorsubassembly in the opposite axial direction and axially adjustable forpresetting the depth of cut of the router, wherein the motor support isa collar and the router bit drive motor subassembly comprises a motormounted within the collar for said axial adjustment, wherein the baseand motor subassemblies have axially spaced opposed annular surfacesencircling the motor, and wherein the spring means comprises a helicalcompression spring interposed between said opposed annular surfaces forbiasing the motor subassembly in said one axial direction.
 2. In aportable router having a base subassembly with a motor support and abottom router supporting face and a router bit drive motor subassemblymounted on the motor support with its axis extending perpendicular tothe router supporting face and for axial adjustment relative to the basesubassembly for adjusting the depth of cut of the router, theimprovement wherein the router comprises spring means axially biasingthe motor subassembly in one axial direction relative to the basesubassembly for retracting the drive motor subassembly, wherein one ofsaid subassemblies comprises a rod extending parallel to the axis ofrelative movement of the subassemblies, wherein the other of saidsubassemblies comprises releasable one-way locking means engageable withthe rod for locking the motor subassembly against movement in said oneaxial direction by the spring means, wherein the router comprisesadjustable stop means for limiting the relative movement of the motorsubassembly in the opposite axial direction and axially adjustable forpresetting the depth of cut of the router, and wherein the releasableone-way locking means comprises a plurality of locking balls around therod, and an annular axially tapered ring surrounding the balls andoperable to wedge the balls into engagement with the rod to lock themotor subassembly against movement in said one axial direction.
 3. Arouter according to claim 1 wherein the motor subassembly comprises aring encircling the motor and having a first of said opposed annularsurfaces and an annular depending skirt encircling said compressionspring, and wherein the base subassembly comprises an annular upstandingshield encircling the compression spring and having a telescopingrelationship with said skirt permitting said axial adjustment of themotor subassembly.
 4. A router according to claim 2 wherein thereleasable one-way locking means comprises a ball cage, cage springmeans for biasing the ball cage in one direction for positioning theballs for being wedged by the ring into locking engagement with the rod,and means for manually retracting the ball cage against the bias of thecage spring means for releasing said locking engagement.
 5. A routeraccording to claim 1 wherein the motor subassembly comprises a sleevesurrounding the motor and having an outer generally cylindrical surfacefor mounting the motor within the collar for said axial adjustment, adepending skirt mounted on said sleeve encircling the compressionspring, router and handle means on the depending skirt.